Reverse osmosis membranes, made by interfacial polymerization of a monomer in a nonpolar (e.g. organic) phase together with a monomer in a polar (e.g. aqueous) phase on a porous support membrane are known as TFC membranes and are used where flux and substantial rejection characteristics are required, for example in the purification of water. Various materials have been added to TFC membranes to increase flux without reducing rejection characteristics and have met with limited success. Such membranes are also subject to fouling resulting in reduced flux as contaminants, for example from the brackish or seawater to be purified, build up on the surface of the discrimination layer of the TFC membrane.
What are needed are techniques for further improving flux while maintaining or improving rejection characteristics, resisting the effects of fouling, as well as techniques for improving commercial processing of such improved TFC membranes.
In one aspect, improved techniques for the use of nanoparticles in TFC membranes have been developed including the combined used of nanoparticles and/or nanotubes with alkaline earth metals, monohydrolyzed TMC and/or other molecular additives in hybrid nanocomposite TFC membranes with increased flux, rejection and anti-fouling characteristics.
In another aspect, the new hybrid nanocomposite TFC membranes, together with more advantages concentrations and ranges of TMC, MPD to TMC ratios as well as the discovery of deflection points in the concentrations of additives, such as monohydrolyzed TMC, make the design and fabrication of engineered nanocomposite TFC membranes with selected flux, rejection and antifouling characteristics possible.
In a further aspect, some of the new additives, particularly the alkaline earth metals and monohydrolyzed TMC, may be used for the design and fabrication of high flux, rejection and anti-fouling TFC membranes. These membranes may also advantageously use the advantageous concentrations and ranges of TMC, MPD to TMC ratios and deflection points in the concentrations of additives to provide optimum characteristics for particular circumstances.
One object of the invention is to provide an interfacial polymerization process for preparing a highly permeable RD membrane, comprising:                contacting on a porous support membrane,                    a) a first solution containing 1,3-diaminobenzene, and            b) a second solution containing trimesoyl chloride,                        wherein at least one of solutions a) and b) contains well dispersed nanoparticles when said solutions are first contacted, and        recovering a highly permeable RD membrane.        
A highly permeable reverse osmosis membrane produced by a process, comprising:                contacting on a porous support membrane,                    a) a first solution containing 1,3-diaminobenzene, and            b) a second solution containing trimesoyl chloride,                        wherein at least one of solutions a) and b) contains well dispersed nanoparticles when said solutions are first contacted, and        recovering a highly permeable RO membrane,        wherein at least 20% of the membrane surface area consists of nanoparticles.                    a) a first solution containing polyamine monomer, and            b) a second solution containing a polyfunctional acyl halide monomer, a                        wherein a molecular additive compound is present in a) or b) or both during the polymerization reaction, and        recovering a highly permeable RO membrane.        
Another object is to provide a highly permeable reverse osmosis membrane, produced by an interfacial polymerization process, comprising:                contacting on a porous support membrane,                    a) a first solution containing a polyamine monomer and            b) a second solution containing a polyfunctional acyl halide monomer,                        wherein a molecular additive compound is present in a) or b) or both during the polymerization reaction, and        recovering a highly permeable RO membrane.        
Another object of the invention is to provide an interfacial polymerization process for preparing a low-fouling highly permeable RO membrane, comprising:                contacting on a porous support membrane,                    a) a first solution containing a polyamine monomer, and            b) a second solution containing a polyfunctional acyl halide monomer,                        wherein aluminum ion is present in a) or b), or both, during the polymerization reaction,        recovering a low-fouling, highly permeable RO membrane.        
Another object is to provide a low-fouling highly permeable RO membrane, produced by an interfacial polymerization process, comprising:                contacting on a porous support membrane,                    a) a first solution containing a polyamine monomer, and            b) a second solution containing a polyfunctional acyl halide monomer,            wherein aluminum ion is present in a) or b), or both, during the polymerization reaction.                        
Another object of the invention is to provide an interfacial polymerization process for preparing a highly permeable RO membrane, comprising:                contacting on a porous support membrane,                    a) an aqueous solution containing metaphenylenediamine (MPD), and            b) an organic solution containing trimesoyl chloride (TMC) and a hydrolyzed TMC species, and                        recovering a highly permeable RO membrane.        
Another object is to provide a highly permeable reverse osmosis membrane, produced by an interfacial polymerization process, comprising:                contacting on a porous support membrane,                    a) an aqueous solution containing metaphenylene diamine (MPD), and            b) an organic solution containing trimesoyl chloride (TMC) and a hydrolyzed TMC species, and                        recovering a highly permeable RO membrane.        